Detergent / anti-oxidant additives for fuels

ABSTRACT

A composition is disclosed that comprises the reaction product of an acidic organic compound, a boron compound, and a basic organic compound. The composition is useful as a detergent additive for lubricants and hydrocarbon fuels.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention is a divisional application of co-pending U.S.application Ser. No. 11/037,623, filed on Jan. 17, 2005, which claimspriority to U.S. Provisional Application No. 60/539,590, filed on Jan.29, 2004, the entire contents and disclosure of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is related to fuels, especially hydrocarbon fuels, andlubricants, especially lubricating oils, and, more particularly, to aclass of reduced ash detergent/anti-oxidant additives that are productsof the reaction of acidic organic compounds, such as hydrocarbylsalicylic acids, basic organic compounds, such as organic nitrogen basecompounds, particularly those comprising an N-hydroxy alkyl moiety, andboron compounds, such as boric acid.

2. Description of Related Art

Metal detergents represent a major source of ash in formulated engineoils. Alkaline earth sulfonates, phenates and salicylates are typicallyused in modern engine oils to provide detergency and alkaline reserve.Detergents are necessary components of engine oils for both gasoline anddiesel engines. Incomplete combustion of the fuel produces soot that canlead to sludge deposits, as well as carbon and varnish deposits. In thecase of diesel fuel, residual sulfur in the fuel burns in the combustionchamber to produce sulfur derived acids. These acids produce corrosionand corrosive wear in the engine, and they also accelerate thedegradation of the oil. Neutral and overbased detergents are introducedinto engine oils to neutralize these acidic compounds, therebypreventing the formation of harmful engine deposits and dramaticallyincreasing engine life.

U.S. Pat. No. 5,330,666 discloses a lubricant oil composition useful forreducing friction in an internal combustion engine which comprises alubricating oil basestock and an alkoxylated amine salt of ahydrocarbylsalicylic acid of a defined formula.

U.S. Pat. No. 5,688,751 discloses that two-stroke cycle engines can beeffectively lubricated by supplying to the engine a mixture of an oil oflubricating viscosity and a hydrocarbyl-substituted hydroxyaromaticcarboxylic acid or an ester, unsubstituted amide,hydrocarbyl-substituted amide, ammonium salt, hydrocarbylamine salt, ormonovalent metal salt thereof in an amount suitable to reduce pistondeposits in said engine. The mixture supplied to the engine containsless than 0.06 percent by weight of divalent metals.

U.S. Pat. No. 5,854,182 discloses the preparation of magnesium borateoverbased metallic detergent having magnesium borate uniformallydispersed in an extremely fine particle size by using magnesium alkoxideand boric acid. The preparation involves reacting a neutral sulphonateof an alkaline earth metal with magnesium alkoxide and boric acid underanhydrous conditions in the presence of a dilution solvent followed bydistillation to remove alcohol and part of dilution solvent therefrom.The borated mixture is then cooled, filtered to recover magnesiumborated metal detergent, which is said to exhibit excellent cleaning anddispersing performance, very good hydrolytic and oxidation stability,and good extreme pressure and antiwear properties.

U.S. Pat. No. 6,174,842 discloses a lubricating oil composition thatcontains from about 50 to 1000 parts per million of molybdenum from amolybdenum compound that is oil-soluble and substantially free ofreactive sulfur, about 1,000 to 20,000 parts per million of adiarylamine, and about 2,000 to 40,000 parts per million of a phenate.This combination of ingredients is said to provide improved oxidationcontrol and improved deposit control to the lubricating oil.

U.S. Pat. No. 6,339,052 discloses a lubricating oil composition forgasoline and diesel internal combustion engines includes a major portionof an oil of lubricating viscosity; from 0.1 to 20.0% w/w of a componentA, which is a sulfurized, overbased calcium phenate detergent derivedfrom distilled, hydrogenated cashew nut shell liquid; and from 0.1 to10.0% w/w of a component B, which is an amine salt of phosphorodithioicacid of a specified formula derived from cashew nut shell liquid.

The disclosures of the foregoing are incorporated herein by reference intheir entirety.

SUMMARY OF INVENTION

According to the present invention, metal-free detergents andanti-oxidants are prepared by reacting an acidic organic compound, aboron compound, and a basic organic compound.

Preferably, the acidic organic compound is selected from the groupconsisting of alkyl substituted salicylic acids, di-substitutedsalicylic acids, oil soluble hydroxy carboxylic acids, salicylic acidcalixarenes, sulfur-containing calixarenes, and the acidic structuresdisclosed in U.S. Pat. Nos. 2,933,520; 3,038,935; 3,133,944; 3,471,537;4,828,733; 6,310,011; 5,281,346; 5,336,278; 5,356,546; and 5,458,793.

Preferably, the basic organic compound is an organic nitrogen basecompound, such as one comprising an N-hydroxy alkyl moiety, preferablyan N-hydroxy or alkoxy alkyl heterocycle, such as N-hydroxy alkylimidazolines, N-alkoxy alkyl imidazolines, or N-hydroxy alkylpiperazines. Other heterocyclics can be pyrrolidine, piperidine,imidazolidine, pyrazolidine, and derivatives of indole, carbazole,quinoline, and the like. Oil soluble and water soluble alkanolamines,including polymeric alkanolamines, such as those described in U.S. Pat.No. 3,692,680 can also be used.

The boron compound can, for example, be boric acid, a trialkyl borate inwhich the alkyl groups preferably comprise from 1 to 4 carbon atomseach, alkyl boric acid, dialkyl boric acid, boric oxide, boric acidcomplex, cycloalkyl boric acid, aryl boric acid, dicycloalkyl boricacid, diaryl boric acid, or substitution products of these with alkoxy,alkyl, and/or alkyl groups, and the like.

The reaction product provides excellent detergency and cleanliness to anoil when evaluated using the panel coker test and excellent antioxidantperformance when evaluated using pressure differential scanningcalorimetry (PDSC).

More particularly, the present invention is directed to a compositioncomprising the reaction product of an acidic organic compound, a boroncompound, and a basic organic compound.

In another aspect, the present invention is directed to a compositioncomprising: (A) a lubricant, and (B) at least one reaction product of anacidic organic compound, a boron compound, and a basic organic compound.

In still another aspect, the present invention is directed to acomposition comprising: (A) a hydrocarbon fuel, and (B) at least onereaction product of an acidic organic compound, a boron compound, and abasic organic compound.

In yet another aspect, the present invention is directed to a method forreducing the formation of deposits in an internal combustion enginewhich comprises operating the engine with a lubricating oil containingthe reaction product of an acidic organic compound, a boron compound,and a basic organic compound in an amount effective to reduce thefriction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention relates to lubricant or fuel compositions, especiallylubricant compositions, comprising an additive comprising boron, whichprovides improved detergency and oxidation stability in an internalcombustion engine oil. The lubricant composition comprises (a) a majoramount of a lubricant, e.g., lubricating oil and (b) a minor amount ofan additive that is the reaction product of an acidic organic compound,a basic organic compound, and a boron compound.

The Acidic Organic Compounds

The acidic organic compounds employed in the practice of the presentinvention include, but are not limited to, alkyl substituted salicylicacids, di-substituted salicylic acids, oil soluble hydroxy carboxylicacids, salicylic acid calixarenes, sulfur-containing calixarenes, andthe acidic structures disclosed in U.S. Pat. Nos. 2,933,520; 3,038,935;3,133,944; 3,471,537; 4,828,733; 6,310,011; 5,281,346; 5,336,278;5,356,546; and 5,458,793.

The substituted salicylic acids employed in the practice of the presentinvention are commercially available or may be prepared by methods knownin the art, e.g., U.S. Pat. No. 5,023,366. These salicylic acids are ofthe formula I:

wherein R¹ is independently a hydrocarbyl group having from 1 to about30 carbon atoms, and a is an integer of 1 or 2. Where a is 2, the R¹groups are independently selected, i.e., they may be the same ordifferent.

As employed herein, the term “hydrocarbyl” includes hydrocarbon as wellas substantially hydrocarbon groups. “Substantially hydrocarbon”describes groups that contain heteroatom substituents that do not alterthe predominantly hydrocarbon nature of the group.

Examples of hydrocarbyl groups include the following:

(1) hydrocarbon substituents, i.e., aliphatic (e.g., alkyl or alkenyl),alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, aromaticsubstituents, aromatic-, aliphatic-, and alicyclic-substituted aromaticsubstituents, and the like, as well as cyclic substituents wherein thering is completed through another. portion of the molecule (that is, forexample, any two indicated substituents may together form an alicyclicradical);

(2) substituted hydrocarbon substituents, i.e., those substituentscontaining non-hydrocarbon groups which, in the context of thisinvention, do not alter the predominantly hydrocarbon nature of thesubstituent; those skilled in the art will be aware of such groups(e.g., halo, hydroxy, mercapto, nitro, nitroso, sulfoxy, etc.);

(3) heteroatom substituents, i.e., substituents that will, while havinga predominantly hydrocarbon character, contain an atom other than carbonpresent in a ring or chain otherwise composed of carbon atoms (e.g.,alkoxy or alkylthio). Suitable heteroatoms will be apparent to those ofordinary skill in the art and include, for example, sulfur, oxygen,nitrogen, and such substituents as, e.g., pyridyl, furyl, thienyl,imidazolyl, etc. Preferably, no more than about 2, more preferably nomore than one, hetero substituent will be present for every ten carbonatoms in the hydrocarbyl group. Most preferably, there will be no suchheteroatom substituents in the hydrocarbyl group, i.e., the hydrocarbylgroup is purely hydrocarbon.

In the formula described above, R¹ is hydrocarbyl. Examples of R¹ informula I above include, but are not limited to,

unsubstituted phenyl;

phenyl substituted with one or more alkyl groups, e.g., methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isomers ofthe foregoing, and the like;

phenyl substituted with one or more alkoxy groups, such as methoxy,ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, octoxy, nonoxy,decoxy, isomers of the foregoing, and the like;

phenyl substituted with one or more alkyl amino or aryl amino groups;

naphthyl and alkyl substituted naphthyl;

straight chain or branched chain alkyl or alkenyl groups containing fromone to fifty carbon atoms, including, but not limited to, methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl,dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl,octadecyl, oleyl, nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl,tetracosyl, pentacosyl, triacontyl, pentatriacontyl, tetracontyl,pentacontyl, isomers of the foregoing, and the like; and

cyclic alkyl groups, such as cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl, and cyclododecyl.

It will be noted that these salicylic acid derivatives can be eithermonosubstituted or disubstituted, i.e., when a in the formula equals 1or 2, respectively.

Salicylic acid calixarenes such as those described in U.S. Pat. No.6,200,936, the content of which is incorporated herein by reference, canbe used as the acid compounds in the reaction products of the presentinvention. Such calixarenes include, but are not limited to, cycliccompounds comprising m units of a salicylic acid of formula IIa:

and n units of a phenol of formula IIb:

joined together to form a ring, wherein each Y is independently adivalent bridging group; R⁰ is independently hydrogen or an alkyl groupof 1 to 6 carbon atoms; R⁵ is independently hydrogen or an alkyl groupof 1 to 60 carbon atoms; and j is 1 or 2; R³ is hydrogen, hydrocarbyl orhetero-substituted hydrocarbyl; either R¹ is hydroxy and R² and R⁴ areindependently hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl,or R² and R⁴ are hydroxyl and R¹ is either hydrogen, hydrocarbyl orhetero-substituted hydrocarbyl; R¹ is independently hydrogen, ahydrocarbyl or a hetero-substituted hydrocarbyl group; m is from 1 to 8;n is at least 3, and m+n is 4 to 20.

When more than one salicylic acid unit is present in the ring (i.e.,m>1), the salicylic acid units (formula IIa) and phenol units (formulaIIb) are distributed randomly, although this does not exclude thepossibility that in some rings there may be several salicylic acid unitsjoined together in a row.

Each Y may independently be represented by the formula (CHR⁶)_(d) inwhich R⁶ is either hydrogen or hydrocarbyl and d is an integer which isat least 1. In one embodiment, R⁶ contains 1 to 6 carbon atoms, and inone embodiment it is methyl. In another embodiment, d is from 1 to 4. Ymay optionally be sulfur rather than (CHR⁶)_(d) in up to about 50% ofthe units, such that the amount of sulfur incorporated in the moleculeis up to about 50 mole %. In one embodiment, the amount of sulfur isbetween about 8 and about 20 mole %. In another embodiment, the compoundis sulfur-free.

For convenience, these compounds are sometimes referred to as“salixarenes” and their metal salts as “salixarates”.

In one embodiment, Y is CH₂; R¹ is hydroxyl; R² and R⁴ are independentlyeither hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; R³ iseither hydrocarbyl or hetero-substituted hydrocarbyl; R⁰ is H; R⁵ is analkyl group of 6 to about 50 carbon atoms, preferably 4 to about 40carbon atoms, more preferably 6 to about 25 carbon atoms; and m+n has avalue of at least 5, preferably at least 6, and more preferably at least8, wherein m is 1 or 2. Preferably, m is 1.

In another embodiment, R² and R⁴ are hydrogen; R³ is hydrocarbyl,preferably alkyl of greater than 4 carbon atoms, and more preferablygreater than 9 carbon atoms; R⁵ is hydrogen; m+n is from 6 to 12; and mis 1 or 2.

For a review of calixarenes, see, e.g., Monographs in SupramolecularChemistry by C. David Gutsche, Series Editor-J. Fraser Stoddart,published by the Royal Society of Chemistry, 1989. Generally,calixarenes having a substituent hydroxyl group or groups includehomocalixarenes, oxacalixarenes, homooxacalixarenes, andheterocalixarenes.

Sulfur-containing calixarenes, e.g., those described in U.S. Pat. No.6,268,320, the contents of which is incorporated herein by reference inits entirety, can also be used as the acid compounds of the presentinvention. Such calixarenes include, but are not limited to, compoundsrepresented by formula (III):

wherein in formula (III): Y is a divalent bridging group, at least oneof said bridging groups being a sulfur atom; R³ is hydrogen or ahydrocarbyl group; either R¹ is hydroxyl and R² and R⁴ are independentlyeither hydrogen or hydrocarbyl, or R² and R⁴ are hydroxyl and R¹ iseither hydrogen or hydrocarbyl; and n is a number having a value of atleast 4.

In formula III, Y is a divalent bridging group or a sulfur atom with theproviso that at least one Y group is a sulfur atom. The divalentbridging group, when not a sulfur atom, can be a divalent hydrocarbongroup or divalent hetero-substituted hydrocarbon group of 1 to 18 carbonatoms, and in a preferred embodiment, 1 to 6 carbon atoms. Theheteroatoms can be —O—, —NH—, or —S—. The integer “n” is an integer thattypically has a value of at least 4, preferably from 4 to 12, and morepreferably, 4 to 8. In one embodiment, n-2 to n-6 of the Y groups aresulfur atoms. In another embodiment n-3 to n-10 of the Y groups aresulfur atoms. In yet another embodiment, one of the Y groups is a sulfuratom. Preferably, the amount of sulfur incorporated in the calixarene isbetween about 5 and about 50 mole %, such that between about 5 and about50% of the groups Y in formula III are sulfur atoms. More preferably,the amount of sulfur is between about 8 and about 20 mole %.

In one embodiment, when Y of formula III is not a sulfur atom, it is adivalent group represented by the formula (CHR⁶)_(d) in which R⁶ iseither hydrogen or a hydrocarbyl group and d is an integer that is atleast one. R⁶ is preferably a hydrocarbyl group of 1 to about 18 carbonatoms, and more preferably, 1 to 6 carbon atoms. Representative examplesof such hydrocarbyl groups include methyl, ethyl, propyl, butyl, pentyl,hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl,tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, isomers or theforegoing, and the like. Preferably, d is from 1 to 3, more preferably 1to 2, and most preferably, d is 1. As defined above, the term“hydrocarbyl groups” includes hetero-substituted hydrocarbyl groups, andare preferably those in which the heteroatom, e.g., —O—, —NH—, or —S—,interrupts a chain of carbon atoms; an example being an alkoxy-alkylgroup of 2 to 20 carbons.

R³ is hydrogen or can be a hydrocarbyl group which may be derived from apolyolefin such as a polyethylene, polypropylene, polybutylene, orpolyisobutylene, or a polyolefin copolymer such as an ethylene/propylenecopolymer. Examples of R³ include dodecyl and octadecyl. Heteroatoms, ifpresent, can again be —O—, —NH—, or —S—. These hydrocarbyl groupspreferably have 1 to about 20 carbon atoms and more preferably, 1 to 6carbon atoms.

Either R¹ is hydroxyl and R² and R⁴ are independently either hydrogen orhydrocarbyl, or R² and R⁴ are hydroxyl and R¹ is either hydrogen orhydrocarbyl. In one embodiment, R¹ is hydrogen, R² and R⁴ are hydroxyl,and R³ is either hydrogen or hydrocarbyl in the formula (III) and thecalixarene is a resorcinarene. The hydrocarbyl groups preferably have 1to about 24 carbon atoms, more preferably 1 to 12 carbon atoms. Theheteroatoms, when present, can be —O—, —NH—, or —S—.

In one embodiment, Y is either sulfur or (CR⁷R⁸)_(e), where either oneof R⁷ and R⁸ is hydrogen and the other is hydrogen or hydrocarbyl; R²and R⁴ are independently either hydrogen or hydrocarbyl, R³ ishydrocarbyl; n is 6; and e is at least 1, preferably 1 to 4, and morepreferably, 1. Preferably, R² and R⁴ are hydrogen and R³ is hydrocarbyl,preferably alkyl of greater than 4, more preferably greater than 9, andmost preferably greater than 12 carbon atoms; and one of R⁷ or R⁸ ishydrogen and the other is either hydrogen or alkyl, preferably hydrogen.

The foregoing sulfur-containing calixarenes typically have a molecularweight below about 1880. Preferably, the molecular weight of thesulfur-containing calixarene is from about 460 to about 1870, morepreferably from about 460 to about 1800, and most preferably from about460 to about 1750.

Acids described in U.S. Pat. Nos. 2,933,520; 3,038,935; 3,133,944;3,471,537; 4,828,733; 5,281,346; 5,336,278; 5,356,546; 5,458,793; and6,310,011, the contents of which are incorporated herein by reference intheir entirety, can also be used as the acid compounds of the presentinvention.

More specifically, such acids include, but are not limited to, compoundsof the formula:

wherein R¹ is hydrocarbon or halogen, R² is hydrocarbon, and Ar issubstituted or unsubstituted aryl. Useful compounds similar to theseinclude 3,5,3′,5′-tetra-substituted 4,4′-dihydroxymethyl carboxylicacids and acids of the formula

wherein X and X′ are independently selected from the group consisting ofhydrogen, hydrocarbyl, halogen, R is polymethylene or branched orunbranched alkylene, and x is 0 or 1, i.e., when x is zero, R is absent,and when x is 1, R is present, and R¹ is hydrogen or hydrocarbyl.

The acids and salts described in U.S. Pat. Nos. 5,281,346; 5,336,278;5,356,546; 5,458,793; and 6,310,011 are similar to the above and arealso contemplated for use in the practice of the present invention, asare those of the formula

wherein R₁ and R₂ are independently selected from the group consistingof hydrogen, hydrocarbyl groups, tertiary alkyl groups, and tertiaryaralkyl groups (but both R₁ and R₂ are not hydrogen) R₃ and R₄ areindependently selected from the group consisting of hydrogen,hydrocarbyl groups, aralkyl groups, and cycloalkyl groups, and x=0 to24.

Oil soluble hydroxy carboxylic acids including, but not limited to,12-hydroxy stearic acid, alpha hydroxy carboxylic acids and the like canalso be employed as the acidic compound of the present invention.

The Basic Organic Compounds

As noted above, the basic organic compound employed in the practice ofthe present invention is preferably an organic nitrogen base compound,such as an one comprising an N-hydroxy alkyl moiety, preferably anN-hydroxy or N-alkoxy alkyl heterocycle, such as N-hydroxy alkylimidazolines, N-alkoxy alkyl imidazolines, and N-hydroxy alkylpiperazines. Other heterocyclics that are within the scope of theinvention include, but are not limited to, pyrrolidines, piperidines,imidazolidines, pyrazolidines, and derivatives of indole, carbazole,quinoline, and the like. Both water soluble and oil solublealkanolamines, including polymeric alkanolamines, such as thosedescribed in U.S. Pat. No. 3,692,680, can also be used. Such polymericalkanolamines can be prepared by reacting a suitable amine with anepichlorohydrin compound. U.S. Pat. No. 3,189,652 discloses such areaction wherein the amine used as a reactant is selected from primaryaliphatic amines containing from 12 to 40 carbon atoms and N-aliphaticpolyamines including N-alkyl-1,3-diamino-propanes in which the alkylcontains at least 12 carbon atoms and N-aliphatic ethylenediamines,N-aliphatic diaminobutanes, -pentanes, -hexanes, and the like in whichthe aliphatic group contains from 12 to 40 carbon atoms.

Other organic nitrogen base compounds that are useful in the practice ofthe present invention include, but are not limited to, those disclosedin U.S. Pat. Nos. 3,446,808; 3,673,186; 3,787,416; the disclosures ofwhich are incorporated herein by reference in their entirety. Suchcompounds include, for example, N-hydroxyalkyl-piperazines-,N-hydroxyalkyl-N′-alkyl piperazines,N-hydroxyalkyl-N′-cycloalkyl-pipera-zines, N-hydroxyalkyl-N′-alkylhexahydropyrimidines, N-hydroxyalkyl-N′-cycloalkyl hexahydropyrimidines,N-hydroxyalkyl-N′-alkyl hexahydropyridazines,N-hydroxyalkyl-N′-cycloalky-1 hexahydropyridazines,N-hydroxyalkyl-piperidines, N-hydroxyalkyl-N′-alkyl-imidazolidines,N-hydroxyalkyl-N′-cycloalkyl-imid-azolidines,N-hydroxyalkyl-pyrrolidine, N-hydroxyalkyl-pyrazolidine,N-hydroxyalkyl-hydrogenated 1,2,3,-triazole, N-hydroxyalkyl-hydrogenated1,2,4,-triazole, N-hydroxyalkyl-hydrogenated indole,N-hydroxyalkyl-hydrogenated carbazole, N-hydroxyalkyl-hydrogenatedquinoline, N-hydroxyalkyl-hydrogenated acridine,N-hydroxyalkyl-hydrogena-ted phenazine,N-oxyalkyl-N′-hydrocarbyl-saturated cyclic diazines,N-hydroxyalkyl-N′-hydrocarbyl-saturated cyclic diazines, andN-alkoxyalkyl-N′-hydrocarbyl-saturated cyclic diazines, wherein thehydrocarbyl moieties are preferably sec-alkyl or cycloalkyl.

Boron Compounds

The boron compound can be, for example, boric acid, a trialkyl borate inwhich the alkyl groups preferably comprise from 1 to 4 carbon atomseach, alkyl boric acid, dialkyl boric acid, boric oxide, boric acidcomplex, cycloalkyl boric acid, aryl boric acid, dicycloalkyl boricacid, diaryl boric acid, or substitution products of these with alkoxy,alkyl, and/or alkyl groups, and the like. Preferably, the boron compoundof boric acid.

The reaction of the boron compound with the acidic and basic compoundsof the present invention can be effected in any suitable manner.

In one method the acidic compound and boron compound are refluxed inpresence of suitable solvents including naphtha and polar solvents suchas water and methanol. After sufficient time the boron compounddissolves whereupon the aminic compound is added slowly to effectneutralization and formation of desired detergent. Diluting oil can beadded as needed to control viscosity, particularly during removal ofsolvents by distillation.

An alcohol, including aliphatic and aromatic alcohols, or a mercaptan,including aliphatic and aromatic mercaptans, can be included in thereaction charge. Preferred aliphatic alcohols include methanol, ethanol,propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol,decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol,hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, isomersthereof, and the like. Preferred aromatic alcohols include phenol,cresol, xylenol, and the like. The alcohol or aromatic phenol moiety maybe substituted with alkoxy groups or thioalkoxy groups. Preferredmercaptans include butyl mercaptan, pentyl mercaptan, hexyl mercaptan,heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan,undecyl mercaptan, dodecyl mercaptan, and the like, as well asthiophenol, thiocresol, thioxylenol, and the like.

The precise structures of the detergent/anti-oxidant additives of thepresent invention are not fully understood. However, in one preferredembodiment, in which a C.sub.16 alkyl salicylic acid was reacted withhydroxyethyl oleic imidazoline (a commercial product) and boric acid,mass spectrometric analysis indicated that the structure of the reactionproduct was:

When a C.sub.16 dialkyl salicylic acid was employed in the reaction, theanalysis indicated the following structural formula:

Those skilled in the art will thus understand that the foregoing leadsto the following generalized structural formula for this particularaspect of the present invention:

wherein R¹ is preferably a hydrocarbyl group, preferably alkyl, of,preferably, from 1 to 50 carbon atoms, more preferably 12 to 30 carbonatoms, most preferably 14 to 18 carbon atoms, a is an integer of 1 or 2(where a is 2, the R¹ groups are independently selected, i.e., they maybe the same or different), and R² is an independently selectedhydrocarbyl group, preferably alkyl or alkenyl, preferably of from 1 to50 carbon atoms, more preferably 12 to 30 carbon atoms, most preferably14 to 18 carbon atoms.

Clearly, the use of alternative starting materials, as described above,will lead to different, but analogous, structures that are within thescope of the present invention.

The additives of the present invention are especially useful ascomponents in many different lubricating oil and fuel compositions. Theadditives can be included in a variety of oils with lubricatingviscosity including natural and synthetic lubricating oils and mixturesthereof. The additives can be included in crankcase lubricating oils forspark-ignited and compression-ignited internal combustion engines. Thecompositions can also be used in gas engine lubricants, turbinelubricants, automatic transmission fluids, gear lubricants, compressorlubricants, metal-working lubricants, hydraulic fluids, and otherlubricating oil and grease compositions. The additives can also be usedin motor fuel compositions.

It is preferred that the compositions of the present invention beincluded in the oil, fuel, or grease in a concentration in the range offrom about 0.01 to about 15 wt %.

Use with other Additives

The additives of this invention can be used as either a partial orcomplete replacement for a detergent currently used. They can also beused in combination with other lubricant additives typically found infuels and motor oils, such as dispersants, anti-wear agents, extremepressure agents, corrosion/rust inhibitors, antioxidants, anti-foamants,friction modifiers, seal swell agents, demulsifiers, Viscosity Index(VI) improvers, metal passivators, and pour point depressants. See, forexample, U.S. Pat. No. 5,498,809 for a description of useful lubricatingoil composition additives, the disclosure of which is incorporatedherein by reference in its entirety.

Examples of dispersants include polyisobutylene succinimides,polyisobutylene succinate esters, Mannich Base ashless dispersants, andthe like. Examples of detergents include neutral and overbased alkaliand alkaline earth metal salts of sulfonic acids carboxylic acids, alkylphenates and alkyl salicylic acids.

Examples of antioxidants include alkylated diphenylamines, N-alkylatedphenylenediamines, phenyl-α-naphthylamine, alkylatedphenyl-α-naphthylamine, dimethyl quinolines, trimethyldihydroquinolinesand oligomeric compositions derived therefrom, hindered phenolics,alkylated hydroquinones, hydroxylated thiodiphenyl ethers,alkylidenebisphenols, thiopropionates, metallic dithiocarbamates,1,3,4-dimercaptothiadiazole and derivatives, oil soluble coppercompounds, and the like. The following are exemplary of such additivesand are commercially available from Crompton Corporation: Naugalube®438, Naugalube 438L, Naugalube 640, Naugalube 635, Naugalube 680,Naugalube AMS, Naugalube APAN, Naugard PANA, Naugalube TMQ, Naugalube531, Naugalube 431, Naugard® BHT, Naugalube 403, and Naugalube 420,among others.

Examples of anti-wear additives that can be used in combination with theadditives of the present invention include organo-borates,organo-phosphites, organo-phosphates, organic sulfur-containingcompounds, sulfurized olefins, sulfurized fatty acid derivatives(esters), chlorinated paraffins, zinc dialkyldithiophosphates, zincdiaryldithiophosphates, phosphosulfurized hydrocarbons, and the like.The following are exemplary of such additives and are commerciallyavailable from The Lubrizol Corporation: Lubrizol 677A, Lubrizol 1095,Lubrizol 1097, Lubrizol 1360, Lubrizol 1395, Lubrizol 5139, and Lubrizol5604, among others.

Examples of friction modifiers include fatty acid esters and amides,organo molybdenum compounds, molybdenum dialkyldithiocarbamates,molybdenum dialkyl dithiophosphates, molybdenum disulfide,tri-molybdenum cluster dialkyldithiocarbamates, non-sulfur molybdenumcompounds and the like. The following are exemplary of such additivesand are commercially available from R.T. Vanderbilt Company, Inc.:Molyvan A, Molyvan L, Molyvan 807, Molyvan 856B, Molyvan 822, Molyvan855, among others. The following are also exemplary of such additivesand are commercially available from Asahi Denka Kogyo K.K.: SAKURA-LUBE100, SAKURA-LUBE 165, SAKURA-LUBE 300, SAKURA-LUBE 310G, SAKURA-LUBE321, SAKURA-LUBE 474, SAKURA-LUBE 600, SAKURA-LUBE 700, among others.The following are also exemplary of such additives and are commerciallyavailable from Akzo Nobel Chemicals GmbH: Ketjen-Ox 77M, Ketjen-Ox 77TS,among others.

An example of an anti-foamant is polysiloxane, and the like. Examples ofrust inhibitors are polyoxyalkylene polyol, benzotriazole derivatives,and the like. Examples of VI improvers include olefin copolymers anddispersant olefin copolymers, and the like. An example of a pour pointdepressant is polymethacrylate, and the like.

Lubricating Oil Compositions

Compositions, when they contain these additives, are typically blendedinto a base oil in amounts such that the additives therein are effectiveto provide their normal attendant functions. Representative effectiveamounts of such additives are illustrated in Table 1.

TABLE 1 Additives Preferred Weight % More Preferred Weight % V.I.Improver about 1 to about 12 about 1 to about 4 Corrosion Inhibitorabout 0.01 to about 3 about 0.01 to about 1.5 Oxidation Inhibitor about0.01 to about 5 about 0.01 to about 1.5 Dispersant about 0.1 to about 10about 0.1 to about 5 Lube Oil Flow Improver about 0.01 to about 2 about0.01 to about 1.5 Detergent/Rust Inhibitor about 0.01 to about 6 about0.01 to about 3 Pour Point Depressant about 0.01 to about 1.5 about 0.01to about 0.5 Anti-foaming Agents about 0.001 to about 0.1 about 0.001 toabout 0.01 Anti-wear Agents about 0.001 to about 5 about 0.001 to about1.5 Seal Swell Agents about 0.1 to about 8 about 0.1 to about 4 FrictionModifiers about 0.01 to about 3 about 0.01 to about 1.5 Lubricating BaseOil Balance Balance

When other additives are employed, it may be desirable, although notnecessary, to prepare additive concentrates comprising concentratedsolutions or dispersions of one or more of the reaction products of thepresent invention, together with one or more other additives wherebyseveral additives can be added simultaneously to the base oil to formthe lubricating oil composition. Dissolution of the additive concentrateinto the lubricating oil can be facilitated by, for example, solventsand by mixing accompanied by mild heating, but this is not essential.The concentrate or additive-package will typically be formulated tocontain the additives in proper amounts to provide the desiredconcentration in the final formulation when the additive-package iscombined with a predetermined amount of base lubricant. Thus, thesubject additives of the present invention can be added to small amountsof base oil or other compatible solvents along with other desirableadditives to form additive-packages containing active ingredients incollective amounts of, typically, from about 2.5 to about 90 percent,preferably from about 15 to about 75 percent, and more preferably fromabout 25 percent to about 60 percent by weight additives in theappropriate proportions with the remainder being base oil. The finalformulations can typically employ about 1 to 20 weight percent of theadditive-package with the remainder being base oil.

All of the weight percentages expressed herein (unless otherwiseindicated) are based on the active ingredient (AI) content of theadditive, and/or upon the total weight of any additive-package, orformulation, which will be the sum of the AI weight of each additiveplus the weight of total oil or diluent.

In general, the lubricant compositions of the invention contain theadditives in a concentration ranging from about 0.05 to about 30 weightpercent. A concentration range for the additives ranging from about 0.1to about 10 weight percent based on the total weight of the oilcomposition is preferred. A more preferred concentration range is fromabout 0.2 to about 5 weight percent. Oil concentrates of the additivescan contain from about 1 to about 75 weight percent of the additivereaction product in a carrier or diluent oil of lubricating oilviscosity.

In general, the additives of the present invention are useful in avariety of lubricating oil base stocks. The lubricating oil base stockis any natural or synthetic lubricating oil base stock fraction having akinematic viscosity at 100° C. of about 2 to about 200 cSt, morepreferably about 3 to about 150 cSt, and most preferably about 3 toabout 100 cSt. The lubricating oil base stock can be derived fromnatural lubricating oils, synthetic lubricating oils, or mixturesthereof. Suitable lubricating oil base stocks include base stocksobtained by isomerization of synthetic wax and wax, as well ashydrocracked base stocks produced by hydrocracking (rather than solventextracting) the aromatic and polar components of the crude. Naturallubricating oils include animal oils, such as lard oil, vegetable oils(e.g., canola oils, castor oils, sunflower oils), petroleum oils,mineral oils, and oils derived from coal or shale.

Many synthetic lubricants are known in the art and these are useful as abase lubricating oil for lubricating compositions containing the subjectadditives. Surveys of synthetic lubricants are contained in thepublications, SYNTHETIC LUBRICANTS by R. C. Gunderson and A. W. Hart,published by Reinhold (N.Y., 1962), LUBRICATION AND LUBRICANTS, E. R.Braithwaite, ed., published by Elsevier Publishing Co., (N.Y., 1967),Chapter 4, pages 166 through 196, “Synthetic Lubricants”, and SYNTHETICLUBRICANTS by M. W. Ranney, published by Noyes Data Corp., (Park Ridge,N.J., 1972). These publications are incorporated herein by reference toestablish the state of the art in regard to identifying both general andspecific types of synthetic lubricants which can be used in conjunctionwith the additives of the present invention.

Thus, useful synthetic lubricating base oils include hydrocarbon oilsderived from the polymerization or copolymerization of olefins, such aspolypropylene, polyisobutylene and propylene-isobutylene copolymers; andthe halohydrocarbon oils, such as chlorinated polybutylene. Other usefulsynthetic base oils include those based upon alkyl benzenes, such asdodecylbenzene, tetra-decylbenzene, and those based upon polyphenyls,such as biphenyls and terphenyls.

Another known class of synthetic oils useful as base oils for thesubject lubricant compositions are those based upon alkylene oxidepolymers and interpolymers, and those oils obtained by the modificationof the terminal hydroxy groups of these polymers, (i.e., by theesterification or etherification of the hydroxy groups). Thus, usefulbase oils are obtained from polymerized ethylene oxide or propyleneoxide or from the copolymers of ethylene oxide and propylene oxide.Useful oils include the alkyl and aryl ethers of the polymerizedalkylene oxides, such as methylpolyisopropylene glycol ether, diphenylether of polyethylene glycol and diethyl ether of propylene glycol.Another useful series of synthetic base oils is derived from theesterification of the terminal hydroxy group of the polymerized alkyleneoxides with mono- or polycarboxylic acids. Exemplary of this series arethe acetic acid esters or mixed C₃-C₈ fatty acid esters of the C₁₃ oxoacid diester of tetraethylene glycol.

Another suitable class of synthetic lubricating oils comprises theesters of dicarboxylic acids with a variety of alcohols. Esters usefulas synthetic oils also include those made from C₅ to C₁₂ monocarboxylicacids and polyols and polyol ethers. Other esters useful as syntheticoils include those made from copolymers of α-olefins and dicarboxylicacids which are esterified with short or medium chain length alcohols.The following are exemplary of such additives and are commerciallyavailable from Akzo Nobel Chemicals SpA: Ketjenlubes 115, 135, 165,1300, 2300, 2700, 305, 445, 502, 522, and 6300, among others.

Silicon-based oils, such as the polyalkyl-, polyaryl-, polyalkoxy-, orpolyaryloxy-siloxane oils and silicate oils, comprise another usefulclass of synthetic lubricating oils. Other synthetic lubricating oilsinclude liquid esters of phosphorus-containing acids, polymerictetrahydrofurans, poly α-olefins, and the like.

The lubricating oil may be derived from unrefined, refined, re-refinedoils, or mixtures thereof. Unrefined oils are obtained directly from anatural source or synthetic source (e.g., coal, shale, or tar andbitumen) without further purification or treatment. Examples ofunrefined oils include a shale oil obtained directly from a retortingoperation, a petroleum oil obtained directly from distillation, or anester oil obtained directly from an esterification process, each ofwhich is then used without further treatment. Refined oils are similarto unrefined oils, except that refined oils have been treated in one ormore purification steps to improve one or more properties. Suitablepurification techniques include distillation, hydrotreating, dewaxing,solvent extraction, acid or base extraction, filtration, percolation,and the like, all of which are well-known to those skilled in the art.Re-refined oils are obtained by treating refined oils in processessimilar to those used to obtain the refined oils. These re-refined oilsare also known as reclaimed or reprocessed oils and often areadditionally processed by techniques for removal of spent additives andoil breakdown products.

Lubricating oil base stocks derived from the hydroisomerization of waxmay also be used, either alone or in combination with the aforesaidnatural and/or synthetic base stocks. Such wax isomerate oil is producedby the hydroisomerization of natural or synthetic waxes or mixturesthereof over a hydroisomerization catalyst. Natural waxes are typicallythe slack waxes recovered by the solvent dewaxing of mineral oils;synthetic waxes are typically the wax produced by the Fischer-Tropschprocess. The resulting isomerate product is typically subjected tosolvent dewaxing and fractionation to recover various fractions having aspecific viscosity range. Wax isomerate is also characterized bypossessing very high viscosity indices, generally having a VI of atleast 130, preferably at least 135 or higher and, following dewaxing, apour point of about −20° C. or lower.

The advantages and the important features of the present invention willbe more apparent from the following examples.

EXAMPLES Detergency Performance—Panel Coker Test

The detergency efficacy of crankcase oils can be assessed in terms ofdeposit forming tendency on a rectangular A1-steel panel in a PanelCoker test. In this test, 200 ml of the test sample is taken in sump andheated at 100° C. For a period of 6 hours, this heated oil is splashedby whiskers on the A1-steel panel, the temperature of which ismaintained at 310° C. After completion of the test, any deposits on thepanel are weighed. A decrease in the weight of deposits as compared witha similar composition lacking the detergent additive indicates improveddetergency.

Antioxidant Performance—Pressure Differential Scanning Calorimetry(PDSC)

PDSC (DuPont Model-910/1090B) can be used for relative antioxidantperformance evaluation of the composition. In this method, a test sample(10 mg) taken in a sample boat is subjected to heating from 100-300° C.at the rate of 10° C. per minute under 500 psi oxygen pressure. Theonset of oxidation temperature is adopted as a criterion for assessmentof antioxidant performance. In general, an increase in onset ofoxidation temperature indicates improvement in antioxidant performance.See J. A. Walker and W. Tsang, “Characterization of Lubrication Oils byDifferential Scanning Calorimetry”, SAE Technical Paper Series, 801383(Oct. 20-23, 1980).

Example 1

A quantity of 40 grams of alkyl (C₁₄-C₁₈) salicylic acid was added to asmall reaction flask equipped with a mechanical stirrer and a condenser.Fifty grams of naphtha was added along with 40 grams of base oil, 15grams of water and 30 grams of methanol. Mixing was started, 15 grams ofboric acid was added, and then the mixture was heated to 70° C. At thattemperature, 48.5 grams of a hydroxy ethyl alkyl imidazoline was addedand the reaction temperature was increased slowly to 210° C. to removevolatiles. A clear brown viscous liquid was recovered that had a totalalkalinity value of 46. The product was subjected to testing as shownbelow.

Panel Coker

Five percent of the above product was added to an SAE 50 base oil,mixed, and subjected to the modified panel coker test. At the end of thetest, the panel was weighed resulting in 6.5 milligrams of deposits.

Pressure Differential Scanning Calorimetry

The sample of Example 1 was subjected to PDSC testing and found to havean induction time of >180 minutes at 165° C. when the test was stopped.

Example 2 Comparative Example

Example 1 was repeated except that the alkyl imidazoline used was anamino ethyl alkyl imidazoline. The final product was a fluid hazy liquidwith poor oil solubility.

Example 3 Comparative Example

Example 1 was repeated but the boric acid was not added. The finalproduct was fluid, bright and clear with very poor panel cokerperformance producing more than 150 milligrams of carbonaceaous deposit.

Example 4 Comparative Example

In this example, the alkyl salicylic acid of Example 1 was replaced withan alkyl aromatic sulfonic acid. The product recovered was clear, buthad extremely poor detergency as measured by 243 milligrams of depositsin panel coker test. The PDSC result was also poor with an inductiontime of only 34.8 minutes.

Example 5

In this example, the amount of alkyl imidazoline was reduced to close tothe theoretical amount of 33 grams required to neutralize the salicylicacid. Excellent detergency was found with panel coker deposits of 3.4milligrams.

In view of the many changes and modifications that can be made withoutdeparting from principles underlying the invention, reference should bemade to the appended claims for an understanding of the scope of theprotection to be afforded the invention.

1-15. (canceled)
 16. A composition comprising: A) a hydrocarbon fuel,and B) at least one reaction product of an acidic organic compound, aboron compound, and a basic organic compound, wherein the reactionproduct is a metal free detergent and wherein the acidic organiccompound is selected from the group consisting of: (A) alkyl substitutedsalicylic acids, (B) di-substituted salicylic acids, (C) oil solublehydroxy carboxylic acids, (D) salicylic acid calixarenes, (E)sulfur-containing calixarenes, (F) acids of the formula:

wherein R₁ is hydrocarbon or halogen, R₂ is hydrocarbon, and Ar issubstituted or unsubstituted aryl. (G) acids of the formula:

wherein X and X′ are independently selected from the group consisting ofhydrogen, hydrocarbyl, and halogen, R is polymethylene or branched orunbranched alkylene, x is 0 or 1, and R¹ is hydrogen or hydrocarbyl, (H)acids of the formula:

wherein R₁ and R₂ are independently selected from the group consistingof hydrogen, hydrocarbyl groups, tertiary alkyl groups, and tertiaryaralkyl groups, provided that both R₁ and R₂ are not hydrogen, R₃ and R₄are independently selected from the group consisting of hydrogen,hydrocarbyl sroups, aralkyl groups, and cycloalkyl groups, and x is from0 to 24, inclusive; and (I) salts of the foregoing acids.
 17. (canceled)18. The composition of claim 16, wherein the boron compound is selectedfrom the group consisting of boric acid, trialkyl borates, alkyl boricacids, dialkyl boric acids, boric oxide, boric acid complex, cycloalkylboric acids, aryl boric acids, dicycloalkyl boric acids, diaryl boricacids, and substitution products of the foregoing with alkoxy groups,alkyl groups, alkyl groups, and combinations thereof.
 19. Thecomposition of claim 16, wherein the basic organic compound is anorganic nitrogen base compound comprising an N-hydroxy alkyl moiety. 20.The composition of claim 16, wherein the basic organic compound isselected from the group consisting of N-hydroxyalkyl-piperazines,N-hydroxyalkyl-N′-alkyl piperazines,N-hydroxyalkyl-N′-cycloalkyl-piperazines, N-hydroxyalkyl-N′-alkylhexahydropyrimidines, N-hydroxyalkyl-N′-cycloalkyl hexahydropyrimidines,N-hydroxyalkyl-N′-alkyl hexahydropyridazines,N-hydroxyalkyl-N′-cycloalkyl hexahydropyridazines,N-hydroxyalkyl-piperidines, N-hydroxyalkyl-N′-alkyl-imidazolidines,N-hydroxyalkyl-N′-cycloalkyl-imidazolidines, N-hydroxyalkyl-pyrrolidine,N-hydroxyalkyl-pyrazolidine, N-hydroxyalkyl-hydrogenated1,2,3,-triazole, N-hydroxyalkyl-hydrogenated 1,2,4,-triazole,N-hydroxyalkyl-hydrogenated indole, N-hydroxyalkyl-hydrogenatedcarbazole, N-hydroxyalkyl-hydrogenated quinoline,N-hydroxyalkyl-hydrogenated acridine, N-hydroxyalkyl-hydrogenatedphenazine, N-oxyalkyl-N′-hydrocarbyl-saturated cyclic diazines,N-hydroxyalkyl-N′-hydrocarbyl-saturated cyclic diazines, andN-alkoxyalkyl-N′-hydrocarbyl-saturated cyclic diazines.
 21. Thecomposition of claim 16, wherein the reaction product is:

wherein R¹ and R² are independently selected hydrocarbyl groups, a is aninteger of 1 or 2, provided that, where a is 2, the R¹ groups areindependently selected.
 22. The composition of claim 21, wherein the R¹and R² groups are independently selected hydrocarbyl groups of from 1 to50 carbon atoms. 23-29. (canceled)
 30. The composition of claim 16,wherein the reaction product is in the range of from about 0.01 to about15 wt % based on the total weight of the composition.
 31. Thecomposition of claim 16, wherein the reaction product is a metal-freedetergent and anti-oxidant.
 32. A composition comprising: A) ahydrocarbon fuel, and B) at least one reaction product of (i) an acidicorganic compound selected from the group consisting of alkyl substitutedsalicylic acids and di-substituted salicylic acids, (ii) a boroncompound, and (iii) an organic nitrogen base compound comprising anN-hydroxy alkyl moiety, and the reaction product is:

wherein R¹ and R² are independently selected hydrocarbyl groups, a is aninteger of 1 or 2, provided that, where a is 2, the R¹ groups areindependently selected.
 33. The composition of claim 32, wherein theboron compound is selected from the group consisting of boric acid,trialkyl borates, alkyl boric acids, dialkyl boric acids, boric oxide,boric acid complex, cycloalkyl boric acids, aryl boric acids,dicycloalkyl boric acids, diaryl boric acids, and substitution productsof the foregoing with alkoxy groups, alkyl groups, alkyl groups, andcombinations thereof.
 34. The composition of claim 32, wherein theorganic nitrogen base compound is selected from the group consisting ofN-hydroxyalkyl-piperazines, N-hydroxyalkyl-N′-alkyl piperazines,N-hydroxyalkyl-N′-cycloalkyl-piperazines, N-hydroxyalkyl-N′-alkylhexahydropyrimidines, N-hydroxyalkyl-N′-cycloalkyl hexahydropyrimidines,N-hydroxyalkyl-N′-alkyl hexahydropyridazines,N-hydroxyalkyl-N′-cycloalkyl hexahydropyridazines,N-hydroxyalkyl-piperidines, N-hydroxyalkyl-N′-alkyl-imidazolidines,N-hydroxyalkyl-N′-cycloalkyl-imidazolidines, N-hydroxyalkyl-pyrrolidine,N-hydroxyalkyl-pyrazolidine, N-hydroxyalkyl-hydrogenated1,2,3,-triazole, N-hydroxyalkyl-hydrogenated 1,2,4,-triazole,N-hydroxyalkyl-hydrogenated indole, N-hydroxyalkyl-hydrogenatedcarbazole, N-hydroxyalkyl-hydrogenated quinoline,N-hydroxyalkyl-hydrogenated acridine, N-hydroxyalkyl-hydrogenatedphenazine, N-oxyalkyl-N′-hydrocarbyl-saturated cyclic diazines,N-hydroxyalkyl-N′-hydrocarbyl-saturated cyclic diazines, andN-alkoxyalkyl-N′-hydrocarbyl-saturated cyclic diazines.
 35. Thecomposition of claim 32, wherein the reaction product is in the range offrom about 0.01 to about 15 wt % based on the total weight of thecomposition.
 36. The composition of claim 32, wherein the reactionproduct is a metal-free detergent.
 37. The composition of claim 32,wherein the reaction product is a metal-free detergent and anti-oxidant.